1. Technical Field
The present invention relates to mechanical systems for and methods of harvesting, storing and converting natural or ambient energy, and more particularly to such systems and methods that utilize the activation of shape memory materials for doing the same.
2. Background Art
Active materials, such as shape memory alloys (SMA) and polymers (SMP), have become increasingly used in the mechanical arts to convert energy harvested from an activation signal into work. Upon deactivation (i.e., termination of exposure to the activation signal) the material typically reverts back to its original state. The use of active material elements, it is appreciated, increases energy efficiency, while reducing weight and complexity in comparison to counterpart electro-mechanical, hydraulic, and pneumatic motors. Concernedly, however, these systems and methods typically rely upon artificially generated signals (such as an electric current, magnetic field, or voltage drop) created by an automated and/or manually initiated source For example, the charging system of a vehicle is often used to drive active material based systems in vehicular settings. Though providing on-demand activation capability, the necessary inclusion of these sources results in increased engineering, construction, operation, and maintenance costs to the overall system.